docs: def time2internaldate(date_time):
      """Convert date_time to IMAP4 INTERNALDATE representation.
  
      Return string in form: '"DD-Mmm-YYYY HH:MM:SS +HHMM"'.  The
      date_time argument can be a number (int or float) representing
      seconds since epoch (as returned by time.time()), a 9-tuple
      representing local time, an instance of time.struct_time (as
      returned by time.localtime()), an aware datetime instance or a
      double-quoted string.  In the last case, it is assumed to already
      be in the correct format.
      """
      if isinstance(date_time, (int, float)):
          dt = datetime.fromtimestamp(date_time, timezone.utc).astimezone()
      elif isinstance(date_time, tuple):
          try:
              gmtoff = date_time.tm_gmtoff
          except AttributeError:
              if time.daylight:
                  dst = date_time[8]
                  if dst == -1:
                      dst = time.localtime(time.mktime(date_time))[8]
                  gmtoff = -(time.timezone, time.altzone)[dst]
              else:
                  gmtoff = -time.timezone
          delta = timedelta(seconds=gmtoff)
          dt = datetime(*date_time[:6], tzinfo=timezone(delta))
      elif isinstance(date_time, datetime):
          if date_time.tzinfo is None:
              raise ValueError("date_time must be aware")
          dt = date_time
      elif isinstance(date_time, str) and (date_time[0],date_time[-1]) == ('"','"'):
          return date_time        # Assume in correct format
      else:
          raise ValueError("date_time not of a known type")
      fmt = '"%d-{}-%Y %H:%M:%S %z"'.format(Months[dt.month])
      return dt.strftime(fmt)